1. Field of the Invention
The present invention relates to a non-contact type tonometer for measuring intraocular pressure of an examinee's eye by blowing a compressed fluid against the cornea of the examinee's eye, and detecting a deformed state of the cornea.
2. Description of Related Art
There is conventionally known a non-contact type tonometer, as disclosed in Japanese Patent Publication No. SHO 63-58577, which measures intraocular pressure of an examinee's eye by blowing a compressed fluid such as air against the examinee's eye, thereby deforming the cornea of the examinee's eye, and directly obtaining a fluid pressure at the time the cornea is deformed into a flattened state from a pressure sensor disposed in a fluid pressure generator.
For an intraocular pressure calculation, however, the conventional tonometer is constructed to use a fluid pressure value at the time a predetermined corneal deformation of an examinee's eye is detected. Thus constructed tonometer has the following problems; for instance, when abnormal piston driving conditions are encountered in the fluid pressure generator, or errors such as a signal error of a pressure sensor caused by noises occur in a pressure detection system, thereby causing variations in pressure, the reliability of intraocular pressure measurement results is lowered.